Leveling out my truck

[bigcarguy]

I have a 72 C10 1/2 ton that sits haunched at the front (the bed sits higher than the front). Anyways, I wanted to level it out so the bed and the front are the same height. I want to lift it so this isn't a lowering question. Would springs from a 3/4ton level it out or is there more that needs to be done? Also, I know this question is probably asked all the time, but what is the widest rim I can put on it with no mods? Thanks for the input.